Good news, gourmets: your truffles are probably not radioactive. Scientists say Burgundy truffles found in radioactive European soil are still safe to eat. The researchers published their findings yesterday in the journal Biogeosciences [PDF].
The lumpy, odiferous fungi called truffles are both a delicacy and something of an environmental alarm system. They grow underground, tapping into soil and tree roots through small filaments called mycelia. Nutrients, minerals, and other environmental molecules accumulate in the truffle. When the soil is rich and healthy, this is a good thing.
But the soil in Europe is not entirely healthy. The Chernobyl nuclear disaster in 1986 released massive amounts of radioactive isotopes like Cesium-137, which quickly spread across the USSR and Europe. Thirty years later, the environment still hasn’t entirely recovered.
"Much of the continent's topsoil layers are still radioactively contaminated," lead author Ulf Büntgen said in a press release. Contamination in the soil seeps into trees and fungi, which are then consumed by animals, disseminating radiation up the food chain. But it seems that some species are affected more than others.
The researchers followed truffle-hunting dogs like Miro (pictured above) through forests and plantations in Switzerland, Germany, France, Italy and Hungary. They were looking specifically for Burgundy truffles (Tuber aestivum), as the truffle’s broad geographic range would allow them to sample the same species in many different locations.
The researchers took their truffles back to the lab. They cleaned the fungi, ground them up, and scanned them for Cs-137. To their surprise, they didn’t find much. “All specimens reveal insignificant radiocaesium concentrations,” the authors wrote in their paper, “thus providing an all clear for truffle hunters and cultivators in Europe as well as dealers and customers from around the world.”
So what’s the deal? Why does T. aestivum get a free radioactivity pass? "We really don't know," Büntgen confessed in the press release. "We will, however, continue to spatially expand our search to include truffles from regions that were so far not considered—the more the better."